THE COORDINATION COMPOUNDS Gd (III) AND Dy(III) WITH SOME β-DIKETONES

Abstract

New complexes of Dy (III) and Gd (III) with b-diketones containing unsaturated and aryl substituents were synthesized. Metal polymers based on synthesized complexes were obtained by the method of radical polymerization. The composition and structure of synthesized complexes and metal polymers are established. It is shown that during polymerization the coordination environment of the central ion remains unchanged. The spectral-luminescent cha­racteristics of the synthesized compounds were studied. The presence of water molecules in the immediate coordination environment causes a low intensity of emission of monomeric dysprosium complexes. In the luminescence spectra of metal polymers, there are bands magnetic dipole transition (4F9 → 6H15/2) and electric dipole transition (4F9 → 6H13/2). The close energies of the triplet level of the ligand and the resonant level of the dysprosium ion cause low emission characteristics of the synthesized dysprosium complexes.

INVESTIGATION OF COORDINATION COMPOUNDS OF GADOLINIUM (III) WITH beta-DIKETONES

“…As can be seen from Table . and fig. the shape and position of the bands in the IR spectra of monomeric, metal-polymer, and heteroligand compounds confirm the bidentate-chelate coordination of the ligands [20,22,24], which is due to the shape and position of the spectral lines in the region of 1400-1600 cm -1 . The oscillations in this part of the spectrum are assigned to as(СС), s(СС) and аs(CO), s(CO).…”

“…Thus, additional donor ligands and polymerization make it possible to purposefully change the emission characteristics of the synthesized compounds. As shown earlier [22,24], the fineness of the synthesized materials has a significant effect on the emission properties; however, there is no general pattern for the entire series of lanthanides; it depends on many factors. These include the electronic structure of the lanthanide ion, the energy of the triplet level of the ligand, and the excitation and emission wavelengths.…”

“…The shift and position of the maxima in the SDR makes it possible to predict differences in the properties of these complexes. Based on quantum chemical calculations, preliminary studies of similar complexes of europium, neodymium, samarium and the isomorphism of gadolinium complexes to them [22,24], the results of chemical and thermal analysis, IR and electron spectroscopy, we can state that monomer and polymer complexes are characterized by no cubic symmetry of the field of ligands, c.n.=8, coordination polyhedron is a square antiprism. The similarity of the spectral characteristics of monomeric, heteroligand and metallopolymeric complexes allows us to assume the following structure of the compounds: To determine the energy of singlet and triplet levels of ligands, it is more correct to record the fluorescence and phosphorescence spectra of gadolinium-containing complexes (Fig.…”

“…The PM7 method was chosen for the calculation. The use of this method in combination with the SPARKLE model, in which the lanthanide atom is represented as a point charge [22], allows obtaining reliable data on the geometry of lanthanide complexes with both aliphatic and aromatic ligands.…”

Investigation of Coordination Compounds of Gadolinium (III) With b-Diketones

“…The PM7 method was chosen for the calcula-tion. The use of this method in combination with the SPARKLE model, in which the lanthanide atom is represented as a point charge, 22 allows obtaining reliable data on the geometry of lanthanide complexes with both aliphatic and aromatic ligands.…”